GIFT   OF 


UNIVERSITY  OF   CALIFORNIA 
DEPARTMENT   OF   CIVIL   ENGINEERING 

TESTING   LABORATORY 


CHARLES    DERLETH,  JR. 
Director 


LABORATORY  INSTRUCTIONS    FOR 

TESTS  OF  METAL,  TIMBER, 

BRICK,  CONCRETE 


BY 

ARTHUR   C.  ALVAREZ 
Instructor  in  Charge 


BERKELEY,  CALIFORNIA 
August,  1912 


PREFACE 


This  manual  has  been  prepared  for  Civil  Engineering  students 
who  take  the  course  in  testing  of  structural  materials  at  the 
University  of  California.  Its  purpose  is  to  expedite  laboratory 
work  by  relieving  the  instructor  from  the  detailed  direction  of 
students. 

A  treatment  of  the  underlying  theoretical  principles  is  not 
included.  For  this  the  student  is  referred  to  earlier  allied  courses 
and  standard  treatises. 

The  main  objects  of  the  course  are  to  acquaint  the  student 
with  the  methods  of  testing  structural  materials,  to  afford  prac- 
tice in  the  writing  of  reports,  and  to  illustrate  the  fundamental 
laws  of  strength  of  materials. 


TABLE  OF  CONTENTS 

PAGE 

General  Eules  for  Laboratory  Work  4 

Operation  of  Testing  Machines 5 

Writing  of  Keports  7 

Part  1.    Tests  of  Metal 

Test 
number  Subject 

1.  Commercial  Tension  Test  of  Metal  8 

2.  Cold  Bending  Test  of  Metal  10 

3.  Elastic  Tension  Test  of  Metal  11 

4.  Commercial  Tension  Test  of  Wire  13 

5.  Tension  Test  of  Wire  Cable  14 

6.  Elastic  Tension  Test  of  Wire  15 

7.  Elastic  Compression  Test  of  Metal  „ 16 

8.  Torsion  Test  of  Metal  17 

9.  Elastic  Torsion  Test  of  Metal  19 

10.  Shearing  Test  of  Metal  21 

11.  Tests  of  Eiveted  Joints  22 

12.  Impact  Flexure  Test  of  Metal  23 

13.  Transverse  Test  of  Cast  Iron  25 

14.  Calibration  of  a  Testing  Machine  26 

Part  2.    Tests  of  Timber 

15.  Flexure  Test  of  Timber  29 

16.  Elastic  Compression  Test  of  Timber  31 

17.  Elastic  Flexure  Test  of  Timber 33 

18.  Impact  Flexure  Test  of  Timber  35 

19.  Impact  Compression  Test  of  Timber  37 

20.  Commercial  Compression  Test  of  Timber  39 

21.  Longitudinal  Shearing  Test  of  Timber  40 

Part  3.    Tests  of  Brick 

22.  Compression  Test  of  Brick  41 

23.  Transverse  Test  of  Brick _ 42 

24.  Absorption  Test  of  Brick  43 

25.  Battler  Test  of  Brick 44 

Part  4.    Tests  of  Concrete 

26.  Elastic  Compression  Test  of  Concrete  45 

27.  Elastic  Flexure  Test  of  Eeinforced  Concrete  Beam  ..  47 


[3] 

402938 


GENERAL  RULES  FOR  LABORATORY  WORK 

Prompt  and  regular  attendance  is  required  of  every  student. 

Tests  are  performed  by  parties  of  three  students  each,  con- 
sisting of  an  operator,  who  manipulates  apparatus;  an  observer 
who  announces  readings;  and  a  recorder,  who  keeps  the  log 
sheets  of  the  test.  Students  are  to  change  positions  in  regular 
order. 

In  making  tests,  students  working  together  share  alike. 
Computations  are  to  be  checked  but  reports  are  to  be  written 
independently. 

The  assignments  of  tests,  materials,  and  testing  machines  are 
posted  on  the  laboratory  bulletin  board.  Directions  for  assigned 
tests  are  to  be  carefully  read  before  coming  to  the  laboratory. 

Upon  completion  of  tests  all  apparatus  used  is  to  be 
thoroughly  cleaned.  All  waste  is  to  be  removed  from  tables, 
floor  and  testing  machines.  All  polished  surfaces  of  metal  are 
to  be  dried  and  oiled. 

Breakage  of  apparatus  is  to  be  reported  immediately. 
Breakages  due  to  carelessness  will  be  charged  to  the  student 
responsible  for  the  damage. 


[4] 


OPERATION  OF  TESTING  MACHINES 

Study  the  operation  of  testing  machines  at  every  opportunity 
and  become  thoroughly  familiar  with  their  principle  and  mech- 
anism. The  machines  in  the  laboratory  are  in  operation  daily; 
students  are  welcome  to  witness  tests  at  any  time. 

Do  not  operate  a  machine  for  the  first  time  without  the 
assistance  of  the  instructor. 

Do  not  start  a  machine  without  determining  the  direction 
and  speed  with  which  it  will  move. 

Do  not  start  a  machine  too  suddenly  as  there  is  danger  of 
stripping  a  gear  or  throwing  a  belt. 

Do  not  change  the  direction  or  speed  without  first  stopping 
the  machine. 

Always  center  the  specimen  accurately  in  the  machine. 

In  compression  tests  always  use  a  spherical  seated  base-plate 
and  adjust  the  upper  bearing  surface  of  the  specimen  parallel 
to  the  upper  plate  of  the  machine. 

In  tension  tests  observe  closely  the  posted  directions  for  use 
of  wedge  grips. 

Before  applying  the  load  in  any  test,  balance  the  weighing 
apparatus  with  the  counterpoise  at  zero  and  the  test  specimen 
in  the  machine.  Adjust  the  recoil  nuts  to  be  just  loose.  Keep 
poise  arm  continually  balanced  as  load  is  being  applied. 

The  speed  of  applying  the  load  in  any  test  must  be  such 
that  the  poise  arm  may  be  kept  balanced  easily.  Always  record 
the  speed.  The  fastest  speed  should  be  used  only  for  shifting 
the  movable  head  to  facilitate  placing  or  removing  specimens. 

Observations  on  a  test  specimen  for  a  certain  indicated  load 
should  be  taken  only  when  the  poise  arm  is  balanced  at  that 
load.  Do  not  move  the  counterpoise  beyond  the  point  at  which 

[5] 


the  failure  occurs  before  taking  the  reading.  As  soon  as  the 
failure  occurs,  throw  the  machine  out  of  gear;  then  record  the 
indicated  load. 

Before  leaving  a  machine,  or  when  a  test  is  finished,  be  sure 
that  the  clutches  are  properly  thrown  out  and  that  the  machine 
has  stopped  running. 

CAUTION. — At  times  machines  have  been  left  running  by 
operators  with  the  result  that  parts  have  been  broken. 

References.    Testing  Machines  and  Methods: 

1.  The  Materials  of  Construction.     Johnson. 

2.  Handbook  of  Testing  Materials.    Martens. 

3.  Biehle  &  Co.     Catalogues  of  Testing  Machines. 

4.  Olsen  &  Co.    Catalogues  of  Testing  Machines. 

5.  Yearbook.    American  Society  for  Testing  Materials. 

6.  Proceedings.     American  Society  for  Testing  Materials. 


[6] 


WRITING  OF  REPORTS 

Follow  strictly  the  "  General  Rules  for  Notes,  Problems, 
Reports  and  Theses,"  adopted  by  the  Department  of  Civil 
Engineering. 

Clearness,  order  of  presentation,  legibility  and  neatness  will 
receive  due  consideration  in  grading  the  report.  Lack  of  neatness 
is  sufficient  cause  for  rejection. 

Observe  the  following  order  in  arranging  the  report  of  each 
test 

Title.    This  should  indicate  at  a  glance  the  scope  of  the  test. 
Purpose.    Give  briefly  the  object  and  significance  of  the  test. 

Material.  Describe  the  materials  tested.  Give  scale  sketches 
of  specimens;  indicate  dimensions;  submit  photographs  of  the 
failures. 

Apparatus.  Name  all  apparatus.  Describe  all  special  ap- 
paratus and  testing  machines  used  for  the  first  time.  Submit 
photograph  of  machine  with  specimen  in  place. 

Method  of  Test.  Describe  all  operations  which  have  any 
bearing  on  the  performance  or  success  of  the  test. 

Data.  Submit  a  log  sheet  of  the  test.  Describe  the  behavior 
of  the  material  when  tested. 

Computations.  State  all  formulas  used ;  define  all  quantities ; 
indicate  numerical  work.  Ordinarily  computations  may  be  made 
with  the  slide  rule.  Submit  final  results  on  report  form  pro- 
vided for  the  test.  Arrange  title  on  stress-strain  diagrams  with 
sufficient  subheadings  to  fully  explain  the  results  obtained. 

Submit  each  report  in  a  standard  folder  within  one  week 
after  the  date  of  performance  of  tests.  Reports  returned  for 
correction  are  due  within  one  week  after  date  of  return. 

NOTE: — In  addition  to  the  prescribed  tests  students  will  be 
held  responsible  for  reference  readings  assigned  at  intervals 
during  the  course.  These  assignments  are  to  be  written  in  the 
manual  under  the  heading  "  References, ' '  of  the  proper  test. 

[7] 


PAET  I.     TESTS  OF  METAL 

TEST  No.  1 
COMMERCIAL  TENSION  TEST  OF  METAL 

Purpose.  To  determine  the  strength  and  ductility  of  various 
metals  when  subjected  to  tension. 

Material.  One  specimen  each  of  steel,  wrought  iron,  Norway 
iron,  brass  and  cast  iron. 

Apparatus.  Testing  machine  arranged  for  tension  test. 
Micrometer  caliper,  steel  scale  graduated  to  one-tenth  of  an  inch, 
pair  6-inch  dividers,  center  punch,  small  hammer,  V-plate,  chalk. 

Operations.  Obtain  with  the  micrometer  caliper  the  average 
dimensions  of  the  net  section  of  each  specimen.  With  center 
punch,  lightly  mark  the  ends  of  a  2-inch  gauge  length  and  divide 
this  length  into  %-inch  spaces.  Chalk  the  surface  at  one  end 
of  the  gauge  length. 

Insert  a  specimen  in  the  machine.  Read  the  directions  for 
operation  of  testing  machines  on  page  5. 

Determine  the  yield  point  by  observing  when  the  poise  arm 
momentarily  drops.  Check  this  load  by  noting  with  the  dividers 
when  the  distance  between  end  punch  marks  begins  to  increase 
rapidly.  Note  the  maximum  load  and  the  load  at  final  rupture. 
Eemove  the  specimen  from  the  machine.  Measure  the  elongation 
between  end  and  adjacent  intermediate  punch  marks.  With  the 
caliper  measure  the  dimensions  of  the  reduced  section.  Observe 
and  record  the  character  of  fracture.  Test  each  specimen  in  a 
similar  manner. 

Report.  Submit  data  on  Form  1  and  summary  of  results  on 
a  second  sheet  of  Form  1. 


[8] 


References : 


[9] 


TEST  No.  2 

COLD  BENDING  TEST   OF  METAL 

Purpose.  To  study  the  ductility  of  metal  when  subjected  to 
cold  bending. 

Material.  One  bar  each  of  medium  steel,  soft  steel,  hard 
steel,  grade  A  wrought  iron. 

Apparatus.    Cold  bending  machine,  steel  scale. 

Operations.  Measure  the  dimensions  of  the  specimens.  Bend 
the  wrought  iron  and  soft  steel  180  degrees  flat  upon  itself; 
the  medium  steel,  180  degrees  about  a  diameter  equal  to  the 
thickness  of  the  material;  the  hard  steel,  180  degrees  about  a 
diameter  equal  to  three  times  the  thickness  of  the  bar.  To  bend 
a  specimen  flat  upon  itself,  first  bend  it  180  degrees  about  a 
diameter  equal  to  its  thickness,  then  complete  the  bend  by  apply- 
ing a  steady  pressure  in  a  testing  machine  arranged  for  com- 
pression. For  each  specimen  note  the  angle  when  cracks  or 
other  signs  of  failure  appear.  Examine  the  bent  portion  care- 
fully. 

Report.    Describe  the  behavior  of  each  specimen  under  test. 

References : 


[10] 


TEST  No.  3 

ELASTIC  TENSION  TEST  OF  METAL 

Purpose.  To  determine  the  coefficient  of  elasticity  and  elastic 
limit  of  metal  when  subjected  to  tension. 

Material.  One  specimen  each  of  medium  steel,  wrought  iron 
and  Norway  iron. 

Apparatus.  Testing  machine  arranged  for  tension  test. 
Micrometer  caliper,  steel  scale  graduated  to  one-tenth  of  an  inch, 
pair  large  dividers,  V-plate,  center  punch,  small  hammer,  Riehle- 
Yale  extensometer  with  battery  and  bell. 

Operations.  With  the  micrometer  caliper  measure  the  diam- 
eter of  each  specimen  at  several  points  throughout  the  turned 
section.  Record  the  mean  value.  Mark  lightly  with  center 
punch  a  gauge  length  of  8  inches  with  intermediate  points  1  inch 
apart.  Attach  extensometer  firmly  with  gauge  bar  set  at  8  inches. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Adjust  specimen  securely  in  the  machine.  Remove  gauge  bar 
from  extensometer.  Read  micrometers  for  an  initial  load  of 
1000  Ib.  and  for  each  1000  Ib.  load  increment  thereafter.  Remove 
extensometer  just  after  reaching  the  elastic  limit. 

Continue  application  of  load  until  failure  occurs.  Obtain 
load  for  each  elongation  increment  of  one-tenth  of  an  inch  as 
determined  with  dividers.  Note  maximum  load  and  load  at 
final  rupture.  Determine  the  percentages  of  elongation  and  con- 
traction as  in  Test  No.  1.  Observe  and  record  the  character  of 
fracture. 

Report.  Submit  data  on  Form  6A  and  summary  of  results  on 
Form  6.  For  each  specimen  construct  two  stress-strain  diagrams 
on  the  same  sheet  of  coordinate  paper,  using  loads  as  ordinates 

[11] 


and  elongations  as  obscissas.  For  diagram  No.  1  use  loads  up  to 
the  elastic  limit  only.  Draw  an  averaging  straight  line  through 
the  plotted  points.  Employ  scales  such  that  this  line  will  make  an 
angle  with  the  X  axis  of  about  60  degrees.  Through  the  origin 
draw  a  second  straight  line  parallel  to  this  line.  Mark  on  it  the 
elastic  limit.  This  second  line  represents  the  true  relation  between 
stress  and  strain  in  the  specimen  up  to  the  elastic  limit.  For 
diagram  No.  2  use  loads  from  elastic  limit  to  rupture  with  the 
origin  the  same  as  for  diagram  No.  1. 

References : 


[12] 


TEST  No.  4 

COMMERCIAL  TENSION  TEST  OF  WIRE 

Purpose.     To  determine  the  strength  and  ductility  of  wire. 

Material.  One  specimen  each  of  soft  steel,  hard  drawn  steel, 
hard  drawn  brass,  hard  drawn  copper,  wire  cable  strands. 

Apparatus.  Wire  testing  machine,  micrometer  caliper,  steel 
scale  graduated  to  one-tenth  of  an  inch,  pair  large  dividers, 
center  punch,  small  hammer,  chalk. 

Operations.  Unravell  the  wire  strands;  note  relative  posi- 
tions of  various  sizes  of  wire.  Obtain  the  average  diameter  of 
each  wire  with  the  caliper.  Test  each  wire  separately,  noting 
only  the  maximum  load. 

Measure  the  diameter  of  each  of  the  other  wire  specimens  at 
three  points  throughout  its  length.  With  center  punch  mark 
lightly  an  8  inch  gauge  length  on  each  wire. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Determine  as  in  Test  No.  1  the  yield  point,  maximum  load, 
load  of  final  rupture,  percentages  of  elongation  and  contraction, 
and  character  of  fracture. 

Report.  Submit  data  on  Form  1  and  summary  of  results  on 
a  separate  sheet  of  Form  1.  Calculate  the  theoretical  strength 
of  the  wire  cable. 

References : 


[13] 


TEST  No.  5 

TENSION  TEST  OF  WIRE  CABLE 

Purpose.    To  determine  the  strength  of  wire  cable. 

Material.  Wire  cable  specimens  with  ends  encased  in  babbit 
metal. 

Apparatus.  Testing  machine  arranged  for  tension  test,  scale, 
caliper. 

Operations.  Measure  the  diameter  of  each  cable.  Count  the 
number  of  strands.  Note  the  number  of  wires  per  strand,  also 
their  diameters. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Obtain  the  ultimate  resistance  of  each  cable.  Note  the  load 
at  which  the  first  wire  ruptures.  Observe  the  manner  of  failure 
of  the  cable. 

Report.  Using  the  data  of  Test  No.  4  calculate  the  efficiency 
of  the  cables.  Draw  enlarged  cross-sectional  sketches  of  each 
specimen. 

References : 


[14] 


TEST  No.  6 
ELASTIC  TENSION  TEST  OF  WIRE 

Purpose.  To  determine  the  coefficient  of  elasticity  and  elastic 
limit  of  wire. 

Material.  One  specimen  each  of  soft  steel,  hard  drawn  steel, 
hard  drawn  brass,  hard  drawn  copper. 

Apparatus.  Wire  testing  machine,  micrometer  caliper,  steel 
scale  graduated  to  one-tenth  of  an  inch,  pair  large  dividers,  wire 
extensometer  with  battery  and  bell. 

Operations.  With  the  caliper  measure  the  diameter  of  each 
wire  at  three  points  throughout  its  length.  Attach  the  extenso- 
meter with  its  micrometers  set  at  zero;  its  gauge  length  is  then 
10  inches. 

Bead  the  directions  for  operation  of  testing  machines  on 
page  5. 

Eead  micrometers  for  an  initial  load  of  50  Ib.  Apply  the 
load  in  regular  increments  such  that  eight  readings  may  be 
obtained  below  the  elastic  limit.  Measure  elongations  with  the 
extensometer  up  to  0.5  inch.  Obtain  the  maximum  load,  per- 
centages of  elongation  and  contraction,  and  character  of  fracture. 

Report.  Submit  data  on  Form  6A  and  summary  of  results 
on  Form  6.  Construct  a  stress-strain  diagram  for  each  specimen 
as  outlined  in  Test  No.  3. 

References : 


[15] 


TEST  No.  7 
ELASTIC  COMPRESSION  TEST  OF  METAL 

Purpose.  To  determine  the  coefficient  of  elasticity  and  elastic 
limit  of  metal  when  subjected  to  compression. 

Material.  One  specimen  each  of  steel,  wrought  iron,  Norway 
iron,  brass  and  cast  iron. 

Apparatus.  Testing  machine  arranged  for  compression  test, 
spherical  seated  base-plate,  hardened  steel  plates,  compressometer 
with  battery  and  bell,  compressometer  collars,  micrometer  caliper. 

Operations.  With  the  micrometer  caliper  measure  the  aver- 
age diameter  of  each  specimen.  Attach  compressometer  collars 
to  specimens,  using  a  2-inch  gauge  length.  Place  the  specimen 
in  the  machine  between  the  hardened  steel  plates. 

Eead  the  directions  for  operation  of  testing  machines  on 
page  5. 

Eead  compressometer  for  an  initial  load  of  1000  Ib.  and  for 
each  3000-lb.  load  increment  thereafter.  When  near  the  elastic 
limit  take  several  readings  with  load  increments  of  1000  Ib. 
Continue  until  the  applied  load  exceeds  the  elastic  limit  by 
20,000  Ib. 

Report.  Submit  data  on  Form  7A  and  summary  of  results 
on  Form  7.  Construct  a  stress-strain  diagram  for  each  specimen 
as  outlined  in  Test  No.  3. 

References : 


[16] 


TEST  No.  8 
TORSION  TEST  OF  METAL 

Purpose.  To  determine  the  strength  of  various  metals  when 
subjected  to  torsion. 

Material.  One  specimen  each  of  steel,  wrought  iron,  Norway 
iron,  brass,  cast  iron. 

Apparatus.  Thurston's  torsion  machine,  platform  scale, 
pendulum  support,  hammer,  punch,  wedges,  micrometer  caliper, 
autographic  diagram  paper,  calibrating  bar,  long  scale. 

Operations.  Calibration  of  Machine.  Place  paper  tightly 
over  recording  drum.  With  pendulum  vertical  release  pencil  and 
by  revolving  drum  draw  a  zero  line.  Determine  weight  of  pen- 
dulum when  in  a  horizontal  position  as  indicated  by  90°  mark 
on  the  wooden  scale.  Measure  lever  arm  and  calculate  maximum 
moment.  With  pendulum  horizontal  draw  a  line  corresponding 
to  the  maximum  moment.  The  maximum  moment  divided  by 
the  distance  between  zero  and  maximum  moment  lines  gives  the 
ordinate  scale  in  inch  pounds  per  inch.  Determine  the  scale  of 
abscissas  in  radians  per  inch. 

Insert  the  calibrating  bar  tightly  with  the  wedges.  Raise  the 
pendulum  with  the  worm  gearing;  the  pencil  will  mark  the 
position  of  approximately  the  zero  ordinate.  Remove  paper  from 
drum  and  mark  it  calibration  sheet. 

Testing  of  Specimens,  With  the  micrometer  caliper  measure 
the  average  diameter  of  the  turned  portion  of  each  specimen. 
For  each  specimen  use  a  new  sheet  of  paper ;  mark  on  each  sheet 
the  line  of  zero  moment.  Tabulate  the  data  on  the  sheet. 

Wedge  the  specimen  tightly  in  place.  With  pendulum 
vertical  readjust  the  pencil  point  accurately  to  the  line  of  zero 
moment.  Apply  the  load  to  the  specimen  by  means  of  the  worm 
gear,  turning  the  crank  with  a  slow  uniform  motion.  Continue 

[17] 


application   of   the   load   until   the   specimen   fails.     Note   the 
character  of  the  fracture. 

Report.    Submit  autographic  diagrams  and  calibration  sheet. 
Report  summary  of  results  on  Form  3. 

References : 


[18] 


TEST  No.  9 

ELASTIC  TORSION  TEST  OF  METAL 

Purpose.  To  determine  the  elastic  properties  of  various 
metals  when  subjected  to  torsion. 

Material.  One  specimen  each  of  steel,  Norway  iron  and 
wrought  iron. 

Apparatus.  Riehle  torsion  machine,  tortometer,  micrometer 
caliper,  scale. 

Operations.  Measure  the  average  diameter  of  the  turned 
portion  of  each  specimen  with  the  micrometer  calipher.  Set  the 
space  bars  on  the  tortometer  for  a  2-inch  gauge  length.  Adjust 
the  tortometer  on  the  specimen,  taking  care  to  have  its  axis 
coincident  with  that  of  the  test  piece.  Place  the  specimen  in 
the  machine  so  that  the  tortometer  dial  arm  is  adjacent  to  the 
stationary  head  and  is  approximately  horizontal.  Move  the 
straining  head  into  position  and  wedge  the  specimen  tightly. 
Set  the  dial  pointers  at  zero  for  an  initial  moment  of  25  foot 
pounds.  Take  readings  to  hundredths  of  a  degree  on  both  dials 
for  moment  increments  of  25  foot  pounds.  In  the  vicinity  of  the 
elastic  limit  use  increments  of  10  foot  pounds.  After  passing 
the  elastic  limit  proceed  with  the  test  at  a  uniform  speed.  Keep 
the  poise  arm  balanced;  note  the  moment  for  each  30  degree 
increment  in  angle  of  twist.  Record  the  maximum  moment,  also 
angle  of  torsion  at  final  rupture.  Note  the  character  of  fracture. 

Report.  Submit  data  on  Form  3A  and  summary  of  results 
on  Form  3.  For  each  specimen  plot  a  curve,  using  moments  as 
ordinates  and  angles  of  torsion  as  abscissas.  Follow  the  method 
outlined  in  Test  No.  3. 


[19] 


References : 


[20] 


TEST  No.  10 
SHEARING  TEST  OF  METAL 

Purpose.  To  determine  the  shearing  strength  of  various 
metals. 

Material.  Turned  lengths  of  steel,  Norway  iron,  wrought 
iron  and  brass. 

Apparatus.  Testing  machine  arranged  for  compression  test, 
metal  shearing  tool,  micrometer  caliper. 

Operations.  With  the  micrometer  caliper  measure  the  diam- 
eter of  each  specimen.  Insert  the  specimen  into  the  shearing 
tool  so  as  to  subject  it  to  single  shear. 

Bead  the  directions  for  operation  of  testing  machines  on 
page  5. 

Obtain  the  maximum  load  and  load  at  final  rupture.  Note 
the  character  of  fracture. 

Report.  Submit  data  and  summary  of  results  on  separate 
sheets  of  Form  4. 

References : 


[21] 


TEST  No.  11 
TESTS   OF  RIVETED  JOINTS 

Purpose.    To  determine  the  strength  of  riveted  joints. 

Material.  Single  lap  joint  with  two  %-inch  rivets,  single 
lap  joint  with  two  %-inch  rivets. 

Apparatus.  Testing  machine  arranged  for  tension  test,  scale, 
caliper. 

Operations.  Measure  the  important  dimensions  of  the  speci- 
mens. 

Head  the  directions  for  operation  of  testing  machines  on 
page  5. 

Insert  filler  plates  on  opposite  sides  in  the  upper  and  lower 
head  of  the  machine  so  that  when  the  load  is  applied  there  is 
no  tendency  to  bend  the  plates  of  the  joint.  Determine  the 
maximum  load.  Describe  the  behavior  of  the  specimen  during 
the  test.  In  what  manner  did  it  fail? 

Report.  Submit  data  and  summary  of  results  on  separate 
sheets  of  Form  4. 

References : 


[22] 


TEST  No.  12 
IMPACT  FLEXURE   TEST   OP   METAL 

Purpose.  To  determine  the  strength,  elastic  properties  and 
manner  of  failure  of  iron  and  steel  in  bending  when  subjected 
to  suddenly  applied  loads. 

Material.  One  beam  each  of  steel  and  wrought  iron  about 
4  feet  long. 

Apparatus.  Turner  impact  testing  machine  arranged  for 
flexure  test,  wrench,  caliper,  scale,  autographic  diagram  paper. 

Operations.  Measure  the  dimensions  of  the  specimens. 
Using  a  span  length  of  36  inches,  clamp  the  specimens  securely 
in  place  and  symmetrically  under  the  hammer.  Attach  the  paper 
to  the  recording  drum  and  see  that  the  stylus  of  the  tuning  fork 
is  properly  adjusted. 

Eead  the  directions  for  operation  of  testing  machines  on 
page  5. 

Lower  the  hammer  so  that  it  just  touches  the  surface  of  the 
specimen;  revolve  the  drum  and  mark  the  datum  line  upon  the 
record.  Record  the  static  deflection  with  the  hammer  resting  on 
the  beam.  Note  the  weight  of  hammer.  Drop  the  hammer  from 
heights  successively  increased  by  a  constant  quantity  until  the 
specimen  fails.  Record  initial  height,  increment  of  height  and 
number  of  drops.  When  hammer  is  about  to  drop,  strike  tuning 
fork  to  cause  it  to  vibrate  and  as  hammer  falls  rotate  the  drum 
slowly,  continuing  until  vibration  of  the  specimen  ceases.  For 
each  drop  measure  the  deflection,  the  rebound  and  the  permanent 
set.  Note  the  nature  of  the  failure.  Use  a  new  sheet  for  each 
test. 

Report.  Submit  data  and  summary  of  results  in  tabular 
form.  Include  a  typical  record  sheet.  Compute  the  fiber  stresses 
at  the  elastic  limit  and  maximum  load,  the  modulus  of  elasticity 

[23] 


and  the  modulus  of  resilence.  For  each  specimen  plot  a  curve, 
using  heights  of  drop  as  ordinates  and  squares  of  deflections  as 
abscissas.  The  point  at  which  the  curve  departs  from  a  straight 
line  indicates  the  elastic  limit. 

References : 


[24] 


TEST  No.  13 
TRANSVERSE  TEST  OF  CAST  IRON 

Purpose.  To  determine  the  flexural  strength  and  eoefficiency 
of  elasticity  of  cast  iron. 

Materials.  Two  specimens  1  x  2  x  26  inches  and  two  speci- 
mens 114  inches  in  diameter  by  14  inches  long. 

Apparatus.  Testing  machine  arranged  for  cross-bending  test, 
scale,  caliper,  deflectometer. 

Operations.    Measure  the  dimensions  of  each  specimen. 

Kead  the  directions  for  operation  of  testing  machines  on 
page  5. 

Test  the  long  specimens  flatwise  with  center  loading  on  a 
24-inch  span.  Read  deflection  for  each  load  increment  of  100  Ib. 
Obtain  maximum  load  and  deflection  for  all  specimens.  Test 
cylindrical  specimens  with  center  loading  on  a  12-inch  span. 
Read  deflections  for  each  load  increment  of  200  Ib. 

Report.  Submit  data  and  summary  of  results  in  tabular 
form.  For  each  specimen  plot  a  curve,  using  center  loads  as 
ordinates  and  deflections  as  abscissas.  Compute  the  modulus  of 
rupture  and  coefficient  of  elasticity  for  each  specimen. 

References : 


[25] 


TEST  No.  14 
CALIBRATION  OF  A  TESTING  MACHINE 

Purpose.  To  compare  the  force  actually  exerted  by  a  testing 
machine  with  the  load  indicated  on  the  dial. 

Apparatus.  Calibrating  bar  of  known  coefficient  of  elasticity, 
testing  machine  to  be  calibrated,  arranged  for  tension  test, 
spherical  seated  screw  grips  to  fit  calibrating  bar,  calibration 
extensometer  with  battery  and  bell. 

Operations.  Attach  extensometer  tightly  and  concentrically 
to  the  calibrating  bar,  using  the  longest  gauge  length  possible, 
Note  the  gauge  length,  the  diameter  of  the  bar  and  its  coefficient 
of  elasticity. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Bead  the  micrometers  for  an  initial  load  of  2000  Ib.  Take 
special  care  to  keep  the  poise  arm  balanced  while  micrometers 
are  being  read.  Take  micrometer  readings  for  increments  of  load 
equal  to  about  one-tenth  of  the  maximum  load  to  be  applied. 
Do  not  exceed  the  safe  load  for  the  bar  which  is  stamped  on  its 
end;  this  load  is  slightly  less  than  its  elastic  limit.  Take  a 
second  set  of  readings  for  the  applied  load,  decreasing  from  the 
maximum  to  the  initial  load. 

Report.  Submit  a  tabular  summary  of  indicated  loads  and 
corresponding  micrometer  readings.  From  the  known  coefficient 
of  elasticity  of  the  calibrating  bar  and  the  observed  strains  com- 
pute the  corresponding  true  loads.  Draw  a  stress-strain  diagram 
using  indicated  loads  as  abscissas  and  observed  strains  as 
abscissas.  On  the  same  sheet  draw  the  true  stress-strain  diagram 
for  the  calibrating  bar.  What  percentage  of  error  do  the  indi- 
cated readings  show? 

[26] 


References: 


[27] 


References : 


[28] 


PART  2.     TESTS  OF  TIMBER 

TEST  No.  15 
FLEXURE   TEST   OF   TIMBER 

Purpose.  To  determine  the  strength  and  coefficient  of  elas- 
ticity of  timber  when  subjected  to  bending. 

Material,    Two  pieces  each  of  Douglas  fir  and  redwood. 

Apparatus.  Testing  machine  arranged  for  flexure  test,  third- 
point  loading  beam,  deflectometer,  scale,  steel  square,  two  steel 
plates,  two  wooden  bolsters,  hammer  and  small  finishing  nails, 
weighing  scale. 

Operations.  Measure  and  weigh  each  specimen.  Count  the 
number  of  annual  rings  per  radial  inch.  Determine  the  per- 
centages of  sapwood  and  heartwood,  also  the  percentages  of 
springwood  and  summerwood.  Make  sketches  showing  end  and 
side  views ;  note  any  defects.  Test  one  beam  of  each  species  with 
center  loading  and  the  other  with  third-point  loading.  Mark 
on  the  sides  of  all  beams  with  pencil  the  center  of  the  span,  also 
the  points  of  load  application  and  support.  Rest  the  deflecto- 
meter on  small  nails  driven  at  the  neutral  surface  over  the  sup- 
ports. Place  the  beam  upon  the  supports,  using  the  steel  plates 
to  prevent  the  knife  edges  from  crushing  the  wood.  Apply  the 
load  through  the  wooden  bolsters.  Adjust  the  deflectometer  to 
read  zero  for  zero  load. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Apply  the  load  in  increments  of  about  one-tenth  of  the 
estimated  ultimate  load.  Read  the  center  deflection  at  each 
increments  of  load  without  stopping  the  machine.  Obtain  the 
maximum  load  and  corresponding  deflection.  Note  the  nature 
of  the  failure. 

[29] 


After  the  test  determine  the  percentage  of  moisture  in  each 
specimen  as  follows:  Cut  a  half-inch  disc  transversely  from  the 
beam  at  the  quarter  point.  Weigh  the  disc  to  one-tenth  of  a 
gram.  Place  it  in  the  drying  oven  at  200°  F.  and  allow  it  to 
dry  until  the  variation  between  two  successive  weights  over  an 
interval  of  twenty-four  hours  is  less  than  0.5  per  cent.  The  loss 
in  weight  expressed  in  percent  of  the  dry  weight  will  give 
approximately  the  moisture  content  of  the  piece  from  which  the 
disc  was  cut. 

Report.  Submit  data  on  Form  5A  and  summary  of  results  on 
Form  5.  Plot  a  curve  for  each  specimen,  using  loads  in  pounds 
as  ordinates  and  center  deflections  in  inches  as  abscissas.  Choose 
scales  such  that  the  slope  of  the  diagram  near  the  origin  will 
be  about  60°.  Mark  the  elastic  limit. 

References : 


[30] 


TEST  No.  16  :%£ 

ELASTIC  COMPRESSION  TEST  OF  TIMBER 

Purpose.  To  determine  the  strength  and  coefficient  of  elas- 
ticity of  wood  when  subjected  to  compression  parallel  to  grain. 

Material.  One  specimen  each  of  Douglas  fir,  redwood  and 
white  oak. 

Apparatus.  Testing  machine  arranged  for  compression, 
spherical  seated  base-plate,  compressometer  with  battery  and  bell, 
compressometer  collars  with  space  bars,  scale,  Harvard  trip 
balance  and  set  of  weights. 

Operations.  Measure  and  weigh  each  specimen.  Count  the 
number  of  annual  rings  per  radial  inch.  Determine  the  per- 
centages of  heartwood  and  sapwood,  also  the  percentages  of 
springwood  and  summerwood.  Make  sketches  showing  end  and 
side  views ;  note  any  deflects.  Attach  the  compressometer  collars 
using  the  longest  gauge  length  possible.  Note  the  gauge  length. 

Head  the  directions  for  operation  of  testing  machines  on 
page  5. 

Make  a  zero  reading  of  the  compressometer  for  an  initial  load 
of  1000  Ib.  Apply  the  load  in  increments  of  about  one-tenth  of 
the  estimated  ultimate  resistance  of  the  specimen.  Stop  the 
machine  after  each  increment  to  obtain  the  compressometer  read- 
ing. Obtain  the  maximum  load  and  corresponding  strain.  Note 
the  kind  of  failure.  Determine  the  percentage  of  moisture  in 
each  specimen  as  outlined  in  Test  No.  15. 

Report.  Submit  data  on  Form  2A  and  summary  of  results 
on  Form  2.  For  each  specimen  construct  a  stress-strain  diagram, 
using  loads  in  pounds  as  ordinates  and  compressions  in  inches 
as  abscissas.  Choose  scales  such  that  the  slope  of  the  diagram 
near  the  origin  will  be  about  60°.  Mark  the  elastic  limit. 

[31] 


References : 


[32] 


TEST  No  17 

ELASTIC  FLEXURE  TEST   OF  TIMBER 

Purpose.  To  determine  the  strength  and  elastic  properties 
of  timber  when  subjected  to  bending  by  experimentally  locating 
the  position  of  the  neutral  surface. 

Material.    One  piece  of  Douglas  fir  4  x  6  x  72  inches. 

Apparatus.  Testing  machine  arranged  for  flexure  test,  third- 
point  loading  beam,  two  grooved  bearing  plates  at  supports,  four 
grooved  bearing  plates  for  applying  load,  two  rollers,  four 
wooden  bolsters,  flexure  strainometer  with  battery  and  bell,  scale, 
steel  square,  nails,  thread,  elastic  band,  deflection  scale,  platform 
scale. 

Operations.  Measure  and  weigh  the  specimen.  Count  the 
number  of  annual  rings  per  radial  inch.  Determine  the  per- 
centages of  sapwood  and  heartwood,  also  the  percentages  of 
springwood  and  summerwood.  Make  sketches  showing  the  end 
and  side  views;  note  any  deflects.  The  load  is  to  be  applied  at 
the  third  points.  Mark  with  pencil  on  the  sides  of  the  beam  the 
center  of  the  span,  the  points  of  load  application  and  support, 
also  the  positions  of  micrometer  collars,  5  inches  on  each  side 
of  the  center.  Attach  micrometer  collars  so  that  both  are  in  the 
same  known  position  with  respect  to  the  beam  cross  section. 
Place  beam  in  machine,  attach  battery  and  bell  to  strainometer. 
Drive  a  small  nail  at  the  neutral  surface  over  each  support. 
Attach  deflection  scale  vertically  at  center  of  beam.  Stretch 
thread  in  front  of  deflection  scale  from  nail  to  nail,  holding  it 
taut  by  an  elastic  band  at  one  end. 

Bead  the  directions  for  operation  of  testing  machines  on 
page  5. 

Take  zero  readings  of  deflection  scale  and  strainometer 
micrometers  fo  ran  initial  load  of  100  Ib.  Take  readings  for 
load  increments  of  250  Ibs.  Eemove  strainometer  after  reach- 

[33] 


ing  elastic  limit.  Determine  the  maximum  load  and  correspond- 
ing deflection.  Note  the  nature  of  the  failure.  Determine  the 
percentage  of  moisture  as  outlined  in  Test  No.  15. 

Report.  Submit  data  on  Form  8A  and  summary  of  results 
on  Form  8.  Plot  a  curve,  using  loads  as  ordinates  and  deflection 
as  abscissas.  On  the  same  sheet  but  with  origins  shifted  along 
the  X  axis,  plot  curves  using  loads,  to  the  same  scale  as  above, 
as  ordinates  and  fibre  strains  as  abscissae.  Mark  the  elastic  limit 
on  these  curves. 

References : 


[34] 


TEST  No.  18 
IMPACT  FLEXURE  TEST  OF  TIMBER 

Purpose.  To  determine  the  strength,  elastic  properties  and 
manner  of  failure  of  wood  in  bending  when  subjected  to  suddenly 
applied  loads. 

Material.    Two  pieces  each  of  Douglas  fir  and  redwood. 

Apparatus.  Turner  impact  testing  machine  arranged  for 
flexure  test,  wrench,  scale,  square,  autographic  diagram  paper, 
weighing  scale. 

Operations.  Measure  and  weigh  each  specimen.  Count  the 
number  of  annual  rings  per  radial  inch.  Determine  the  per- 
centages of  sapwood  and  heartwood,  also  the  percentages  of 
springwood  and  summerwood.  Make  sketches  showing  the  end 
and  side  views ;  note  any  defects.  Mark  with  pencil  on  the  sides 
of  each  beam  the  center  of  the  span  and  points  of  support. 
Clamp  the  specimen  securely  in  place  and  symmetrically  under 
the  hammer.  Attach  the  paper  to  the  recording  drum  and  see 
that  the  stylus  of  the  tuning  fork  is  properly  adjusted. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Lower  the  hammer  so  that  it  just  touches  the  surface  of  the 
specimen;  revolve  the  drum  and  mark  the  datum  line  upon  the 
record.  Record  the  static  deflection  with  the  hammer  resting  on 
the  beam.  Note  the  weight  of  hammer.  Drop  the  hammer 
from  heights  successively  increased  by  a  constant  quantity  until 
the  specimen  fails.  Record  initial  height,  increment  of  height 
and  number  of  drops.  When  hammer  is  about  to  drop,  strike 
tuning  fork  to  cause  it  to  vibrate  and  as  hammer  falls,  rotate 
the  drum  slowly,  continuing  until  vibration  of  the  specimen 
ceases.  For  each  drop  measure  the  deflection,  the  rebound  and 
the  permanent  set.  Note  the  nature  of  the  failure.  Use  a  new 
sheet  for  each  test  unless  the  sheet  is  less  than  half  covered. 

[35] 


Determine  the  percentage  of  moisture  in  each  specimen  as  out- 
lined in  Test  No.  15. 

Report.  Submit  data  in  tabular  form  and  summary  of  results 
on  Form  10.  Include  a  typical  autographic  diagram.  For  each 
specimen  plot  a  curve  using  heights  of  drop  as  ordinates  and 
squares  of  deflections  as  abscissas.  Mark  the  elastic  limit. 

References : 


[36] 


TEST  No.  19 
IMPACT  COMPRESSION  TEST  OF  TIMBER 

Purpose.  To  determine  the  strength  of  timber  in  compression 
when  subjected  to  suddenly  applied  loads. 

Material.  One  specimen  each  of  Douglas  fir,  redwood  and 
white  oak. 

Apparatus.  Turner  impact  machine  arranged  for  compres- 
sion test,  wrench,  scale,  autographic  diagram  paper,  scale. 

Operations.  Measure  and  weigh  each  specimen.  Count  the 
number  of  annual  rings  per  radial  inch.  Determine  the  per- 
centages of  sapwood  and  heartwood,  also  the  percentages  of 
springwood  and  summerwood.  Make  sketches  showing  the  end 
and  side  views ;  note  any  defects.  Clamp  the  specimen  securely 
in  place  and  symmetrically  under  the  hammer.  Attach  the  paper 
to  the  recording  drum  and  see  that  the  stylus  of  the  tuning 
fork  is  properly  adjusted.  Note  the  weight  of  the  hammer. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Carefully  lower  the  hammer  until  it  rests  on  the  specimen. 
Revolve  the  drum  and  mark  the  datum  line  upon  the  record. 
Drop  the  hammer  from  heights  successively  increased  by  a  con- 
stant quantity  until  the  specimen  fails. 

Record  initial  height,  increment  of  height  and  number  of 
drops.  When  the  hammer  is  about  to  drop,  strike  tuning  fork 
to  cause  it  to  vibrate  and  as  hammer  falls,  rotate  the  drum 
slowly,  continuing  until  vibration  of  specimen  ceases.  For  each 
drop  measure  the  deflection,  the  rebound  and  the  permanent  set. 
Note  the  nature  of  the  failure.  Use  a  new  sheet  for  each  test 
unless  the  sheet  is  less  than  half  covered.  Determine  the  per- 
centage of  moisture  in  each  specimen  as  outlined  in  Test  No.  15. 

[37] 


Report.  Submit  data  in  tabular  form  and  summary  of  results 
on  form  similar  to  Form  10.  Include  a  typical  autographic 
diagram.  For  each  specimen  plot  a  curve,  using  heights  of  drop 
or  ordinates  and  squares  of  deflections  as  abscissas.  Mark  the 
elastic  limit. 

References : 


[38] 


TEST  No.  20 

COMMERCIAL  COMPRESSION  TEST  OF  TIMBER 

Purpose.  To  determine  the  strength  of  timber  when  sub- 
jected to  compression  parallel  and  perpendicular  to  grain. 

Material.  Two  specimens  each  of  Douglas  fir  and  redwood 
for  compression  parallel  to  grain  and  two  specimens  each  of 
Douglas  fir  and  redwood  for  compression  perpendicular  to  grain. 

Apparatus.  Testing  machine  arranged  for  compression  test, 
spherical  seated  base-plate,  platform  scale,  measuring  scale. 

Operations.  Measure  and  weigh  each  specimen.  Count  the 
number  of  annual  rings  per  radial  inch.  Determine  the  per- 
centages of  heartwood  and  sapwood,  also  the  percentages  of 
springwood  and  summerwood.  Make  sketches  showing  the  end 
and  side  views;  note  any  defects. 

Eead  the  directions  for  operation  of  testing  machines  on 
page  5. 

Determine  the  maximum  load  and  nature  of  failure  for  each 
specimen.  Determine  percentage  of  moisture  as  outline  in  Test 
No.  15. 

Report.    Submit  data  and  summary  of  results  in  tabular  form. 

References : 


[39] 


TEST  No.  21 
LONGITUDINAL  SHEARING  TEST  OF  TIMBER 

Purpose.  To  determine  the  strength  of  timber  when  sub- 
jected to  shear  parallel  to  grain. 

Material.  Two  specimens  each  of  Douglas  fir,  redwood  and 
white  oak. 

Apparatus.  Testing  machine  arranged  for  compression  test, 
wood  shearing  tool,  measuring  scale,  wrench,  weighing  scale. 

Operations.  Measure  and  weigh  each  specimen.  Count  the 
number  of  annual  rings  per  radial  inch.  Determine  the  per- 
centages of  sapwood  and  heartwood,  also  the  percentages  of 
springwood  and  summerwood.  Make  sketches  showing  the  end 
and  side  views;  note  any  defects.  Place  the  specimen  in  the 
shearing  tool,  tightening  the  screws  so  that  it  is  rigidly  held. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Determine  the  maximum  load  for  each  specimen.  Note  the 
position  of  the  failure. 

Report.  Submit  data  and  summary  of  results  on  separate 
sheets  of  Form  4. 

References : 


[40] 


PART  3.     TESTS  OF  BRICK 

TEST  No.  22 

COMPRESSION  TEST  OF  BRICK 

Purpose.  To  determine  the  crushing  strength  of  brick  when 
subjected  to  compression  edgewise  and  flatwise. 

Material.    Three  building  brick,  three  paving  brick. 

Apparatus.  Testing  machine  arranged  for  compression, 
spherical  seated  base-plate,  weighing  scale,  plaster  Paris,  capping- 
plates,  measuring  scale. 

Operations.  Note  the  brand  of  each  brick.  Measure  and 
weigh  each  specimen.  If  the  capacity  of  the  testing  machine  will 
not  permit  of  testing  a  whole  brick,  test  half  of  the  specimen. 
Coat  the  bearing  surfaces  with  a  layer  of  plaster  Paris  about 
one-quarter  of  an  inch  thick;  cap  this  squarely  with  the  cast- 
iron  plates.  If  the  bearing  surfaces  are  smooth  blotting  paper 
may  be  substituted  for  the  plaster  Paris. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Test  the  building  brick  flatwise  and  the  paving  brick  edge- 
wise. Obtain  the  crushing  load. 

Report.     Submit  data  and  summary  of  results  on  separate 
sheets  of  Form  11. 
References : 


[41] 


TEST  No.  23 
TRANSVERSE  TEST  OF  BRICK 

Purpose.    To  determine  the  modulus  of  rupture  of  brick. 
Material.    Three  building  brick,  three  paving  brick. 

Apparatus.  Testing  machine  arranged  for  cross-bending  test, 
special  supports  for  transverse  testing,  measuring  scale,  square, 
weighing  scale. 

Operations.  Note  the  brand  of  each  brick.  Measure  and 
weigh  each  specimen.  Test  the  building  brick  flatwise  and  the 
paving  brick  edgewise.  Mark  with  pencil  on  the  sides  of  each 
brick  the  center  of  the  span  and  points  of  support  7  inches  apart. 

Eead  the  directions  for  operation  of  testing  machines  on 
page  5. 

Obtain  the  maximum  center  load  for  each  brick.  Note  the 
character  of  the  fracture.  Save  the  half  bricks  resulting  from  the 
test  for  making  compression  and  absorption  tests. 

Report.  Submit  data  and  summary  of  results  on  separate 
sheets  of  Form  11A. 

References : 


[42] 


TEST  No.  24 
ABSORPTION  TEST  OF  BRICK 

Purpose.  To  determine  the  percentage  of  water  absorbed  by 
brick. 

Material.    One-half  of  each  brick  tested  transversely. 
Apparatus.     Drying  oven,  thermometer,  Harvard  trip  bal- 
ance, set  of  weights,  blotting  paper,  water  storage  tank. 

Operations.  Mark  and  weigh  each  sample.  Dry  the  samples 
in  the  oven  at  200°  F.  until  the  difference  between  two  successive 
weights  taken  twenty-fours  apart  is  less  than  0.5  per  cent.  Note 
the  weight  of  each  brick  when  dry.  Submerge  the  specimens 
completely  in  the  water  storage  tank.  Reweigh  each  sample 
after  periods  of  one-half  hour,  two  hours  and  twenty-four  hours. 
Before  each  weighing  remove  the  excess  surface  moisture  with 
blotting  paper. 

Report.  Submit  data  and  summary  of  results  on  separate 
sheets  of  Form  11.  Determine  the  percentage  of  absorption  by 
weight  in  terms  of  the  weight  of  the  dry  specimen. 

References : 


[43] 


TEST  No.  25 

RATTLER  TEST  OF  BRICK 

Purpose.  To  determine  the  resistence  of  brick  to  impact  and 
abrasion. 

Material.  Enough  paving  brick  of  one  kind  so  that  their 
total  volume  will  be  as  nearly  as  possible  equal  to  8  per  cent  ol 
the  volume  of  the  rattler. 

Apparatus.  Standard  rattler  recommended  by  the  National 
Paving  Brick  Manufacturers'  Association,  standard  charge  of 
shot,  platform  scale,  rule,  wrench. 

Operations.  See  that  the  specimens  are  clean  and  dry  before 
testing.  Measure  and  weigh  each  specimen.  Place  the  brick 
with  the  charge  of  shot  in  the  rattler  and  close  the  cylinder. 
Rotate  the  rattler  through  1800  revolutions  at  a  speed  of  not 
less  than  29%  nor  more  than  30y2  revolutions  per  minute.  Note 
the  exact  speed.  Reweigh  the  specimens.  Compute  the  loss  in 
terms  of  the  initial  weight  of  dry  brick. 

Note  the  condition  of  the  staves  of  the  cylinder,  also  the 
condition  of  the  shot.  Obtain  the  total  weight  of  each  kind  of 
shot. 

Report.  Submit  data  in  tabular  form  and  summary  or  results 
on  Form  11A. 

References : 


[44] 


PART  4.     TESTS  OF  CONCRETE 

TEST  No.  26 

ELASTIC  COMPRESSION  TEST  OF  CONCRETE 

Purpose.  To  determine  the  coefficient  of  elasticity  and 
strength  of  concrete. 

Material.    One  8  x  16  inch  concrete  cylinder. 

Apparatus.  Testing  machine  arranged  for  compression, 
spherical  seated  base-plate,  two  capping  plates,  plaster  Paris, 
compressometer  with  battery  and  bell,  compressometer  collars 
with  space  bars,  weighing  scale. 

Operations.  Note  the  kinds  and  proportions  of  constituent 
materials,  also  the  age  of  the  specimen.  Weigh  the  specimen. 
Coat  the  ends  with  a  layer  of  plaster  Paris  about  one-quarter  of 
an  inch  thick.  Cap  the  plaster  Paris  with  plates  placed  squarely 
on  the  specimen.  Attach  the  compressometer  collars,  using  the 
longest  gauge  length  possible.  Note  the  gauge  length. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

Apply  a  load  of  2000  Ib. ;  allow  the  specimen  to  stand  with 
this  load  applied  while  the  plaster  Paris  is  setting.  Make  a 
zero  compressometer  reading  for  an  initial  load  of  2000  Ib.  Read 
compressometer  at  each  load  increment  of  2000  Ib.  until  the 
first  crack  appears  on  the  surface  of  the  specimen.  Then  remove 
the  compressometer  and  obtain  the  maximum  load.  Note  the 
method  of  failure. 

Report.  Submit  data  and  summary  of  results  in  tabular 
form.  Compute  the  coefficient  of  elasticity  for  unit  stresses  of 
500  Ib.  per  square  inch,  1000  Ib.  per  square  inch,  and  1500  Ib. 
per  square  inch.  Draw  a  stress-strain  diagram,  using  loads  as 
ordinates  and  compressions  as  abscissas. 

[45] 


References : 


[46] 


TEST  No.  27 

ELASTIC  FLEXURE  TEST  OF  REINFORCED 
CONCRETE  BEAM 

Purpose.  To  determine  the  strength  and  elastic  properties 
of  reinforced  concrete  when  subjected  to  bending  by  experi- 
mentally locating  the  position  of  the  neutral  surface. 

Material.    One  reinforced  concrete  beam  4  x  6  x  72  inches. 

Apparatus.  Testing  machine  arranged  for  flexure  test,  third- 
point  loading  beam,  two  grooved  bearing  plates  at  supports,  four 
grooved  bearing  plates  for  applying  load,  two  rollers,  four 
wooden  bolsters,  flexure  strainometer  with  battery  and  bell, 
plaster  Paris,  scale,  steel  square,  thread,  elastic  band,  deflection 
scale,  thread  holders,  platform  scale. 

Operations.  Note  the  kinds  and  proportions  of  constituent 
materials,  also  the  age  of  the  specimen.  Measure  and  weigh  the 
beam.  The  load  is  to  be  applied  at  the  third  points;  the  deflec- 
tion is  to  be  measured  at  the  center.  Mark  with  pencil  on  the 
sides  of  the  beam  the  center  of  the  span,  the  points  of  load 
application  and  support,  also  the  positions  of  micrometer  collars, 
5  inches  on  each  side  of  the  center.  Attach  micrometer  collars 
so  that  both  are  in  the  same  known  position  with  respect  to  the 
beam  cross-section;  the  lower  screws  are  to  be  fastened  directly 
on  to  the  steel  reinforcement  rods.  Place  beam  in  the  machine. 
Attach  a  thread  holder  at  the  neutral  surface  over  each  support. 
Cushion  the  grooved  bearing  plates  at  the  third  points  with  a 
thin  layer  of  plaster  Paris.  Paste  deflection  scale  with  plaster 
Paris  vertically  at  center  of  span.  Stretch  the  thread  between 
holders  and  directly  in  front  of  deflection  scale,  holding  it  taut 
by  an  elastic  band  at  one  end.  Attach  battery  and  bell  to 
strainometer. 

Read  the  directions  for  operation  of  testing  machines  on 
page  5. 

[47] 


Take  zero  readings  of  deflection  scale  and  strainometer 
micrometers  for  an  initial  load  of  100  Ib.  Take  readings  for 
load  increments  of  100  Ib.  up  to  1000  lb| ;  for  load  increments  of 
250  Ib.  thereafter.  Remove  the  strainometer  when  the  first 
indication  of  failure,  other  than  a  tension  crack  at  the  bottom  of 
the  beam,  appears.  Determine  the  maximum  load  and  corre: 
spending  deflection.  Note  the  nature  of  the  failure. 

Report.  Submit  data  on  Form  9A  and  summary  or  results 
on  Form  9.  Plot  a  curve  using  loads  as  ordinates  and  deflections 
as  abscissas.  On  the  same  sheet  but  with  origins  shifted  along 
the  X  axis,  plot  curves  using  loads,  to  the  same  scale  as  above,  as 
ordinates  and  fibre  strains  in  steel  and  concrete  as  abscissas. 

References : 


[48] 


UNIVERSITY  OF  CALIFORNIA 
DEPARTMENT  OF  CIVIL  ENGINEERING 

TESTING   LABORATORY 


CHARLES  DERLETH,  JR. 

DIRECTOR 


LABORATORY  INSTRUCTIONS  FOR  TESTS 

OF  MACADAM  AND  BITUMINOUS 

ROAD  MATERIALS 


BY 
ARTHUR  C.  ALVAREZ 


CONTENTS 

Test 
Number  Subject  Page 

MACADAM  BOCK 

28  Abrasion  49 

29  Cementation  51 

30  Hardness  53 

31  Toughness  54 

ASPHALT 

32  Penetration    .  ..  55 

33  Volitilization 57 

34  Solubility  59 

35  Extraction  from  Mineral  Aggregate 62 

36  Melting  Point 63 

37  Fixed  Carbon 65 

38  Ductility  66 

OIL 

39  Flash  Point 68 

40  Viscosity 69 


PART  5 

TESTS  OF  ROAD  MATERIALS 


MACADAM    ROCK 


TEST  No.  28 
ABRASION  TEST 

Purpose.  To  determine  the  resistance  of  macadam  rock  to 
wear. 

Material.  Two  samples  of  different  kinds  of  stone  each  con- 
taining at  least  30  Ib.  of  2J  in.  crushed  rock  of  uniform  size. 

Apparatus.  Deval  abrasion  machine,  balance  sensitive  to  one- 
tenth  of  a  gram,  with  metric  weights,  brush,  two  pans,  0.16  cm. 
(%6in.)  mesh  sieve. 

Operations.  See  that  the  rock  is  dry.  Brush  the  separate 
particles  free  of  any  adhering  foreign  matter.  If  the  rock  is 
very  dirty,  scrub  it  in  water ;  then  dry  it  thoroughly.  Weigh  out 
to  the  nearest  tenth  of  a  gram  a  test  sample  of  each  kind  of  rock 
amounting  to  5  kilograms  within  10  grams.  Each  test  sample 
should  contain  as  nearly  fifty  pieces  as  possible. 

Unseal  two  of  the  cylinders;  brush  out  all  dust  from  within. 
Put  one  of  the  weighed  test  samples  into  each  cylinder  and  reseal. 
Start  the  machine  and  rotate  the  cylinders  for  10,000  revolutions 
as  indicated  by  the  automatic  counter.  Note  the  rate  of  revolu- 
tion ;  it  should  be  between  30  and  33  per  minute. 

Remove  the  abraded  charge  from  one  of  the  cylinders  into  the 
pan.  Brush  out  all  the  fine  dust.  Brush  off  individually  all  the 
particles  larger  than  J  in.  and  set  them  aside  for  weighing. 
Screen  all  the  remainder  through  the  No.  16  sieve.  Add  the 
residue  to  the  particles  larger  than  J  in.  and  weigh.  The  portion 
which  passes  the  No.  16  sieve  is  considered  abraded  material; 

[49] 


determine  its  amount  by  subtracting  from  the  weight  of  the 
original  charge,  the  weight  of  material  of  the  abraded  charge 
which  will  not  pass  the  No.  16  sieve.  Express  the  amount  of 
abraded  material  in  two  ways:  1.  As  a  percentage  by  weight 
of  the  original  charge;  2.  As  the  French  coefficient  of  wear 

400 
which  equals — -—,  where  W  is  the  weight  of  abraded  material  in 

grams  per  kilogram  of  original  charge.  In  a  similar  manner 
determine  the  amount  of  wear  for  the  abraded  sample  in  the 
second  cylinder. 

Give  the  principal  dimensions  of  the  Deval  machine.  On  a 
sheet  of  8J  x  11  in.  decimal-inch  coordinate  paper  plot  a  curve 
having  as  abscissas  French  coefficients  of  wear  up  to  20  and  as 
ordinates  corresponding  percentages  of  wear.  This  curve  is  for 
future  reference  to  assist  in  transferring  from  one  system  of 
results  to  the  other.  So  far  as  indicated  by  its  resistance  to  wear, 
what  is  the  value  of  this  rock  as  a  material  for  macadam  roads? 

References. 

1.  Bulletin  44,  Office  of  Public  Eoads,  U.  S.  Department  of  Agricul- 

ture. 

2.  Columbia  School  of  Mines  Quarterly,  Vol.  26,  No.  2,  pp.  83-110. 

3.  Proceedings,  American  Society  for  Testing  Materials,  Vol.  13,  pp. 

983-995. 

4.  Yearbook,  1914,  American  Society  for  Testing  Materials,  p.  338. 


[50] 


TEST  No.  29 

CEMENTATION  TEST  OF  MACADAM  ROCK 

Purpose.  To  determine  the  binding  power  of  macadam  rock 
dust. 

Material.  A  sample  of  crushed  rock  containing  at  least  500 
gm.  of  J-in.  material. 

Apparatus.  Ball  mill,  briquette  former,  Page  impact  machine 
equipped  with  one-kilogram  hammer,  five  sheets  of  metallic  re- 
cording paper,  box  of  pasters,  hot-air  bath,  desiccator,  brush, 
spatula,  4-in.  glass  plate,  shellac  and  brush,  250  cc.  glass  graduate, 
balance  sensitive  to  one-tenth  of  a  gram  with  metric  weights, 
briquette  spacer,  screw  driver. 

Operations.  Remove  upper  segment  of  the  ball  mill  and 
thoroughly  clean  the  interior  of  both  parts.  Thoroughly  clean 
the  rock  sample ;  if  necessary,  wash  it  on  a  screen.  Put  500  gm. 
of  the  sample  and  about  90  cc.  of  water  into  the  mill  and  bolt 
the  top  segment  tightly  in  place.  Start  the  mill  and  grind  for 
2J  hours ;  the  speed  of  rotation  should  be  about  2000  revolutions 
per  hour ;  note  the  speed.  Remove  the  paste  from  the  mill  with 
the  spatula.  The  paste  should  be  stiff. 

Mould  this  paste  into  cylinders,  usually  called  briquettes,  in 
the  briquette  forming  machine.  These  briquettes  are  25  mm.  in 
diameter;  determine  by  trial  the  amount  of  paste  required  to 
make  a  briquette  25  mm.  high  after  the  pressure  has  been  applied. 
After  sufficient  paste  for  one  briquette  has  been  put  into  the 
compression  chamber  and  the  cap  has  been  screwed  tightly  into 
place,  balance  the  poise  arm  for  zero  load.  Then  gradually  apply 
loading  up  to  a  total  of  1429  Ib.  (132kg.  per  sq.  cm.  of  paste). 
Make  the  total  period  during  which  the  paste  is  in  compression 
from  zero  to  1429  Ib.  equal  to  30  seconds.  The  maximum  load 
should  be  applied  only  for  an  instant.  Remove  the  briquette  and 
place  it  on  the  4-in.  square  of  glass.  Be  careful  not  to  injure  it. 
Mould  seven  briquettes. 

[51] 


Allow  the  briquettes  to  dry  on  the  glass  plate  for  20  hours  in 
air  at  room  temperature.  Then  in  the  hot-air  bath  at  200°  fahr. 
for  4  hours,  then  cool  for  20  minutes  in  the  desiccator. 

Test  the  briquettes  in  the  Page  impact  machine.  Place  with 
two  pasters  a  sheet  of  metallic  paper  around  the  recording  drum. 
Measure  to  one-tenth  of  a  millimeter  the  height  of  the  briquette 
to  be  tested.  Set  the  spacer  at  this  height  and  insert  it  between 
the  table  of  the  machine  and  the  flat  surface  of  the  spherical- 
seated  bearing  in  the  crosshead.  With  the  spacer  in  this  position, 
which  the  briquette  will  occupy,  adjust  by  trial  the  automatic 
release  for  zero  drop  of  hammer. 

Note  the  scale  reading;  then  advance  the  release  1  cm.,  which 
will  give  the  hammer  a  drop  of  this  amount.  Place  the  specimen 
symmetrically  under  the  spherical-seated  bearing;  to  prevent 
shifting  under  impact  fasten  it  to  the  table  of  the  machine  with 
some  shellac.  Clamp  the  spring  of  the  recording  lever  so  that  the 
pointer  presses  firmly  against  the  drum.  Start  the  machine  and 
test  the  briquette  to  destruction.  Test  the  best  five  briquettes. 

The  number  of  blows  up  to  the  one  when  the  resilience  of  the 
briquette  is  destroyed  indicates  the  binding  power  of  the  dust. 
Tabulate  the  results  and  compute  the  mean  number  of  blows  for 
the  briquettes  tested.  So  far  as  indicated  by  the  binding  power 
of  its  dust  what  is  the  value  of  this  rock  for  macadam  roads  ? 

References. 

1.  Bulletin  44,  Office  of  Public  Eoads,  U.  S.  Department  of  Agricul- 

ture. 

2.  Columbia  School  of  Mines  Quarterly,  Vol.  26,  No.  2,  pp.  83-110. 

3.  Eoads  and  Pavements,  Baker,  1905  edition,  pp.  177-195. 


[52] 


TEST  No.  30 

HARDNESS  TEST  OF  MACADAM  ROCK 

Purpose.    To  determine  the  hardness  of  macadam  rock. 

Material.  Two  samples  of  different  kinds  of  stone,  each  con- 
sisting of  a  cylindrical  rock  core,  25  mm.  in  diameter,  squared  at 
both  ends  and  about  1J  in.  long. 

Apparatus.  Dorry  hardness  machine,  abrasive  agent  con- 
sisting of  standard  quartz  sand,  size  between  30  and  40  mesh, 
balances  sensitive  to  one  centigram  with  metric  weights. 

Operations.  Weigh  each  rock  core  to  the  nearest  centigram. 
Insert  the  rock  cores  into  the  holders  and  clamp.  Put  the  holders 
in  position  so  that  the  cores  bear  on  the  revolving  table.  Each 
holder  weighs  1250  gm.  Between  the  bottom  of  each  core  and 
the  grinding  surface  of  the  revolving  cast  iron  table  spread  a 
layer  of  quartz  sand  about  one  grain  deep  and  extend  this  layer 
slightly  beyond  the  adjacent  sand  feed.  Start  the  machine  and 
rotate  the  table  for  1000  revolutions.  Feed  the  sand  so  as  to 
give  always  a  continuous  grinding  layer  between  specimens  and 
table  as  the  latter  revolves.  Then  weigh  the  specimens  and, 
reversing  them  end  for  end  in  the  holders,  repeat  the  grinding  for 
another  1000  revolutions.  Weigh  both  specimens  again. 

The   hardness   of   a   specimen   is   given   by   the   expression 

W 

H  =  2Q — — ,  where  H  is  the  coefficient  of  hardness  and  W  is 
3 

loss  in  weight  of  core  in  grams  per  1000  revolutions. 

Tabulate  the  four  results  and  calculate  the  mean  values. 
What  is  the  value  of  this  rock  for  macadam  road  construction  so 
far  as  indicated  by  its  hardness? 

References. 

1.  Bulletin  44,  Office  of  Public  Koads,  U.  S.  Department  of  Agrciul- 

ture. 

2.  Proceedings,  American  Society  for  Testing  Materials,  Vol.  13,  pp. 

983-995. 

[53] 


TEST  No.  31 

TOUGHNESS  TEST  OF  MACADAM  ROCK 

Purpose.    To  determine  the  toughness  of  macadam  rock. 

Material.  Two  samples  of  different  kinds  of  stone,  each  con- 
sisting of  a  cylindrical  rock  core  25  mm.  in  diameter  and  25  mm. 
high,  squared  at  both  ends- 
Apparatus.  Page  impact  machine  equipped  with  2-kilogram 
hammer  and  plunger  with  hardened  steel  hemispherical  contact 
of  1  cm.  radius. 

Operations.  Center  one  of  the  cylinders  under  the  plunger 
and  by  trial  adjust  the  automatic  release  for  zero  drop  of  the 
hammer.  Note  the  scale  reading.  Subject  the  cylinder  to  drops 
of  the  hammer  successively  increased  from  zero  by  one  centimeter. 
Keep  the  cylinder  well  centered  under  the  hemispherical  portion 
of  the  plunger.  The  number  of  blows  required  to  destroy  the 
cylinder  represents  the  toughness.  Test  the  other  cylinder 
similarly. 

So  far  as  indicated  by  its  toughness  what  is  the  value  of  this 
rock  for  macadam  road  construction  ?  How  does  the  classification 
of  the  rock  as  determined  by  individual  toughness  and  hardness 
tests  compare  with  that  determined  by  the  abrasion  test  ? 

References. 

1.  Bulletin  44,  Office  of  Public  Eoads,  U.  S.  Department  of  Agricul- 

ture. 

2.  Yearbook,  1914,  American  Society  for  Testing  Materials,  p.  340. 

3.  Proceedings,  American   Society  for  Testing  Materials,  Vol.   13, 

pp.  983-995. 


[54] 


ASPHALT 

TEST  No.  32 

PENETRATION  TEST 

Purpose.  To  measure  the  consistency  of  asphaltic  cement  at 
various  temperatures. 

Material.    Three  sample  cans  of  asphalt. 

Apparatus.  Penetrometer,  metronome,  glass  cup  with  sample- 
can  holder,  large  agate  pan,  asphalt  thermometer,  agate  pitcher, 
Bunsen  burner,  iron  ring  stand. 

Operations.  The  penetration  of  bitumen  is  the  distance  in 
hundredths  of  a  centimeter  that  a  No.  2  cambric  needle  will 
penetrate  vertically  at  77°  fahr.  The  weight  under  which  the 
needle  penetrates  and  the  period  of  time  during  which  this  weight 
is  applied  should  always  be  reported.  These  are  made  to  depend 
upon  the  consistency  of  the  bitumen  and  are  determined  by 
measuring  the  penetration  first  for  a  weight  of  100  grams  and  a 
period  of  5  seconds.  If  the  penetration  is  less  than  10,  it  should 
be  determined  using  a  weight  of  200  grams  applied  for  1  minute ; 
but  if  the  first  penetration  is  between  10  and  300,  it  should  be 
determined  using  a  weight  of  100  grams  applied  for  5  seconds; 
w^hile  if  the  first  penetration  is  greater  than  300,  it  should  be 
determined  using  a  weight  of  50  grams  applied  for  5  seconds. 
Whenever  possible  the  penetration  should  be  measured  using  a 
100  gram  weight  applied  for  5  seconds  in  addition  to  the  pene- 
tration measured  for  any  other  stated  weight  and  time  as  above 
required.  When  the  penetration  is  greater  than  100,  the  con- 
tainer should  not  be  less  than  1J  in.  in  diameter.  The  penetra- 
tion should  be  determined  at  temperatures  of  32°  fahr.,  77°  fahr., 
and  114.8°  fahr. 

To  determine  the  penetration,  heat  some  water  in  the  agate 
pan  up  to  a  temperature  of  77°  fahr.,  then  remove  the  pan  from 
the  burner  and  immerse  the  three  sample  cans  of  bitumen  in  the 
water  for  at  least  30  minutes.  Stir  occasionally  with  the  asphalt 

[55] 


thermometer  and  maintain  this  temperature  by  the  addition  of 
hot  water  as  required  from  time  to  time  as  long  as  any  samples 
remain  in  the  pan.  Clean  the  needle.  Remove  one  of  the  samples 
to  the  holder  in  the  glass  cup  on  the  penetrometer  stand ;  nearly 
fill  this  cup  with  warm  water  from  the  pan  and  place  it  under 
the  needle.  Lower  the  frame  holding  the  needle  until  the  needle 
point  almost  touches  the  surface  of  the  bitumen.  Clamp  the 
needle  in  exact  contact  with  the  surface  of  the  asphalt  by  observ- 
ing through  the  side  of  the  glass  cup  its  reflection  from  the  sur- 
face of  the  sample.  Add  to  the  frame  the  proper  weight  so  that 
when  released  the  needle  will  be  under  a  total  load  of  100  gm. 
Bring  the  rack  down  gently  to  the  top  of  the  rod  of  the  needle 
frame  and  rotate  the  dial  to  read  zero.  Unclamp  the  needle  frame 
for  5  seconds  as  determined  by  the  metronome;  then  reclamp. 
Again  lower  the  rack  as  before.  The  pointer  on  the  dial  then 
indicates  the  penetration  in  hundredths  of  a  centimeter.  The 
water  in  the  glass  cup  should  be  maintaied  at  a  temperature  of 
77°  fahr.  while  the  penetration  is  being  measured.  Proceed  in 
testing  this  sample  according  to  the  directions  in  the  first  para- 
graph under  the  heading,  "Operations."  Make  three  deter- 
minations of  the  penetration  on  the  sample.  Repeat  with  the 
other  two  samples. 

Determine  by  the  above  methods  the  penetration  for  each  of 
the  three  samples  of  bitumen ;  also  at  temperatures  of  114.9°  fahr. 
and  32°  fahr. 

Tabulate  the  results ;  compute  the  mean  for  each  temperature. 

What  factors  determine  the  penetration  of  bitumen  to  specify 
for  any  given  case?  Tabulate  desirable  values  under  several 
varying  conditions. 

References. 

1.  Bulletin  38,  Office  of  Public  Koads,  U.  S.  Department  of  Agricul- 

ture. 

2.  The  Modern  Asphalt  Pavement,  Kichardson,  pp.  559-567. 

3.  Yearbook,  1914,  American  Society  for  Testing  Materials,  p.  344. 

4.  Proceedings,  American  Society  for  Civil  Engineers,  Vol.  40,  No. 

10,  Dec.,  1914,  pp.  2997-3050. 

5.  Proceedings,    American    Society    for    Testing    Materials,    1915. 

Eeport  of  Committee  D-4  with  appendices. 

[56] 


TEST  No.  33   , 

VOLATILIZATION  TEST 

Purpose.  To  determine  the  losses  in  weight  and  penetration 
after  heating  asphalt. 

Material.    One  sample  can  of  bitumen  containing  about  20  gm. 

Apparatus.  Constant-temperature  hot-air  oven,  two  chemical 
thermometers  reading  from  0°  to  250°  C.  Analytic  balance  sensi- 
tive to  half  a  milligram  with  metric  weights,  tin  container,  stir- 
ring rod,  container  with  fluid  bitumen. 

Operations.  The  sample  should  be  free  of  water.  The  con- 
tainer should  be  a  cylindrical  tin  box  about  2  cm.  deep  and  6  cm. 
in  diameter  or  of  such  size  as  to  give  the  same  relation  between 
area  of  exposed  surface  of  asphalt  and  its  volume.  The  sample 
is  to  be  heated  for  five  hours  in  the  oven  at  a  constant  tempera- 
ture of  163°  C.  (325°  fahr.).  If  it  foams  at  this  temperature 
there  is  water  in  the  bitumen.  To  remove  the  water  heat  the 
bitumen  for  five  hours  at  a  temperature  of  220°  fahr. 

After  removal  of  the  water  but  before  heating  the  sample 
determine  its  penetration  at  77°  fahr.  according  to  the  method 
outlined  in  Test  No.  32. 

Bring  the  oven  to  a  uniform  temperature  of  163°  C.  (325° 
fahr.)  as  determined,  while  the  air  fans  are  driven  by  the  clock, 
by  the  thermometers  inserted  through  the  stoppers  in  the  holes 
of  the  cover  to  the  level  that  the  sample  will  occupy.  The  bulb 
of  one  thermometer  should  be  in  air,  the  bulb  of  the  other  in  the 
container  of  fluid  bitumen.  Warm  some  of  the  sample,  just 
enough  to  handle  conveniently,  then  put  sufficient  into  the  tin 
container  to  weigh  20  gm.  within  0.2  gm.  After  cooling  weigh 
container  with  bitumen  to  the  nearest  0.5  mlgm.  Put  the  con- 
tainer with  bitumen  to  be  tested  in  the  oven  at  163°  C.  and  allow 
it  to  remain  there  for  five  hours.  During  this  period  the  ther- 
mometers should  not  show  a  variation  in  temperature  from  163° 
C.  greater  than  2°  C.  Then  remove  the  container,  allow  it  to 
cool,  then  reweigh  it.  Note  any  change  in  its  external  appearance. 

[57] 


Determine  the  penetration  of  the  residue  at  77°  fahr.  in  the 
way  this  was  measured  before  the  sample  was  heated.  But  before 
determining  the  penetration,  melt  the  residue  and  stir  it  thor- 
oughly until  it  cools. 

Calculate  the  losses  in  weight  and  penetration  in  amount  and 
in  percentage. 

What  do  large  losses  in  weight  on  heating  signify?  What 
allowable  losses  should  be  specified  under  different  conditions? 

References. 

1.  Bulletin  38,  Office  of  Public  Roads,  IT.  S.  Department  of  Agricul- 

ture. 

2.  Yearbook,  1914,  American  Society  for  Testing  Materials,  p.  345. 

3.  The  Modern  Asphalt  Pavement,  Eichardson,  pp.  534-538,  554-555. 


[58] 


TEST  No.  34 

SOLUBILITY  TESTS 

Purpose.  To  determine  the  percentages  of  bitumen  which  are 
soluble  in  carbon  bisulphide,  in  naphtha  and  in  carbon  tetra- 
chloride. 

Material.  Sample  of  about  20  gm.  of  asphalt;  some  carbon 
bisulphide,  carbon  tetrachloride ;  also  60°  Baume  and  88°  Baume 
naphtha,  all  chemically  pure. 

SOLUBILITY   IN  CARBON   BISULPHIDE 

Apparatus.  One  200  cc.  Erlenmeyer  flask  with  cork,  three 
prepared  porcelain  Gooch  crucibles,  hot-air  oven,  desiccator, 
analytic  balance  sensitive  to  half  a  milligram  with  metric . 
weights,  one  500  cc.  filtering  flask,  wash  bottle  with  solvent,  ther- 
mometer reading  from  — 10°  to  110°  C.,  Bunsen  burner,  iron 
tripod,  platinum  crucible,  porcelain  triangle. 

Operations.  Dry  the  Gooch  crucible  for  ten  minutes  in  the 
oven  at  100°  C.,  then  ignite  it  at  a  low  red  heat  over  the  Bunsen 
burner ;  cool  in  the  desiccator  and  weigh  to  0.5  mlgm.  Clean  and 
dry,  then  weigh  the  flask,  then  introduce  about  2  gm.  of  bitumen ; 
obtain  exact  weight  of  bitumen  by  weighing  flask  plus  bitumen. 
Pour  in  small  portions  into  the  flask  about  100  cc.  of  CS2  and 
agitate  continually  until  all  lumps  disappear.  Loosely  cork  the 
flask  and  set  it  aside  for  about  fifteen  to  thirty  minutes  to  allow 
subsidence  of  the  residue. 

Place  the  Gooch  crucible  in  position  for  filtering.  Decant  the 
solution  from  the  flask  through  the  filter  without  suction,  but 
be  careful  not  to  disturb  any  of  the  settled  residue.  Stop  de- 
cantation  as  soon  as  sediment  begins  to  come  and  let  the  filter 
drain.  Add  more  solvent  to  the  flask.  Agitate,  then  allow  to 
settle  and  decant  as  before.  After  the  filter  is  drained,  pour  on 
the  residue.  With  solvent  remove  to  the  filter  any  residue  which 
adheres  to  the  flask  and  wash  the  residue  on  the  filter  until  the 
filtrate  is  colorless.  Apply  suction  until  the  odor  of  solvent  dis- 

[59] 


appears  from  the  crucible ;  then  wash  the  outside  of  the  crucible 
with  some  CS2.  CAUTION:  Be  careful  in  using  CS2;  its  vapor  is 
inflammable.  Dry  the  crucible  with  residue  in  the  oven  at  100°  C. 
for  about  twenty  minutes,  then  cool  in  the  desiccator  and  weigh. 

The  insoluble  residue  may  contain  both  organic  and  mineral 
matter.  Burn  off  the  former  by  ignition  in  the  crucible  at  a  red 
heat  until  no  incandescent  particles  remain.  After  cooling  in  a 
desiccator  reweigh  the  crucible  and  determine  the  percentage  of 
mineral  matter.  If  the  mineral  matter  is  finely  divided  it  will 
pass  through  the  felt  of  the  Gooch  crucible. 

Check  this  determination  of  the  mineral  matter  by  making  to 
0.5  mlgm.  the  necessary  weighings  and  igniting  in  the  platinum 
crucible  a  1  gram  sample  of  bitumen.  When  the  mineral  matter 
is  finely  divided  it  may  be  determined  more  accurately  by  ignition 
of  an  original  sample  than  by  ignition  of  the  residue  on  the  Gooch 
crucible. 

Report  the  percentage  of  bitumen  soluble;  also  the  percent- 
ages of  organic  and  mineral  matter  insoluble  on  the  basis  of  the 
weight  of  material  taken  for  analysis.  Of  what  value  is  the  test 
for  solubility  in  CS2  ? 

References. 

1.  Bulletin  38,  Office  of  Public  Beads,  U.  S.  Department  of  Agricul- 

ture. 

2.  Yearbook,  1914,  American  Society  for  Testing  Materials,  pp.  342- 

343. 

3.  The  Modern  Asphalt  Pavement,  Kichardson,  pp.  540-542,  589-594. 


SOLUBILITY  IN  NAPHTHA 

Apparatus.  Same  as  for  determining  the  solubility  of  bitumen 
in  carbon  bisulphide,  hydrometer. 

Operations.  With  the  hydrometer  check  the  specific  gravity 
of  each  kind  of  naphtha  used  as  solvent.  If  necessary  bring  each 
to  its  proper  density  by  dilution  with  a  heavier  or  lighter 
naphtha  as  required.  Follow  the  procedure  outlined  for  measur- 
ing solubility  in  CS2.  Consult  the  references  before  coming  to 

[60] 


the  laboratory.  Consult  the  instructor  if  the  bitumen  does  not 
dissolve  readily.  In  filtering  use  suction  only  when  filtration  by 
gravity  ceases,  and  then  use  it  sparingly,  since  it  tends  to  clog 
the  filter.  If  much  insoluble  matter  adheres  to  the  flask  do  not 
attempt  to  remove  it  completely  but  wash  it  thoroughly  with 
solvent,  then  dry  both  flask  and  crucible  for  about  one  hour  at 
100°  C.,  then  cool  and  weigh. 

The  percentage  of  material  insoluble  in  naphtha  minus  the 
percentage  of  material  insoluble  in  carbon  bisulphide  equals  the 
percentage  of  bitumen  which  is  insoluble  in  the  former  on  the 
basis  of  total  material  taken  for  analysis.  In  reporting  results 
this  percentage  should  be  given  on  the  basis  of  total  bitumen 
soluble  in  carbon  bisulphide.  If  x  equals  the  percentage  of 
material  insoluble  in  naphtha  and  y  that  insoluble  in  CS2, 
then  the  percentage  of  bitumen  insoluble  in  naphtha  equals 

sp  n  t 

—  X  100  on  the  required  basis. 
Of  what  significance  is  this  test  of  bitumen  ? 
References. 

1.  Bulletin  38,  Office  of  Public  Eoads,  U.  S.  Department  of  Agricul- 

ture. 

2.  The  Modern  Asphalt  Pavement,  Kichardson,  pp.  542-544,  592. 

SOLUBILITY  IN  CARBON  TETRACHLORIDE 

Apparatus.  Same  as  for  determining  solubility  of  bitumen 
in  carbon  bisulphide. 

Operations.  Follow  the  directions  for  determining  solubility 
in  CS2  except  the  CC14  is  to  be  the  solvent. 

Report  the  percentage  of  bitumen  insoluble  on  the  basis  of 
total  bitumen  soluble  in  CS2  as  100  per  cent. 

For  what  purpose  is  solubility  of  bitumen  in  carbon  tetra- 
chloride  determined? 

References. 

1.  Bulletin  38,  Office  of  Public  Koads,  U.  S.  Department  of  Agricul- 

ture. 

2.  The  Modern  Asphalt  Pavement,  Eichardson,  pp.  124,  546,  590. 

[61] 


TEST  No.  35 

EXTRACTION  OF  BITUMEN  FROM  MINERAL 
AGGREGATE 

Purpose.  To  determine  the  percentage  of  bitumen  in  a  sample 
of  wearing  surface. 

Material.    About  150  gm.  of  wearing  surface. 

Apparatus.  Dulin  Rotarex,  500  cc.  carbon  bisulphide,  bal- 
ance sensitive  to  1  centigram,  hammer,  small  chisel,  1J  in.  stiff 
brush,  600  cc.  beaker,  sheet  of  manila  paper. 

Operations.  Chisel  the  sample  into  particles  about  J  in.  in 
size,  weigh  out  accurately  50  gm.  and  place  in  the  bowl  of  the 
extractor.  Put  the  paper  filter  hinge  in  place,  then  the  cover  of 
the  bowl.  Fasten  the  cover  by  screwing  down  tightly  by  hand  the 
inlet  nozzle  for  solvent.  Introduce  sufficient  solvent  to  cover 
the  sample  and  allow  a  few  minutes  for  digestion.  Place  the 
beaker  under  the  outlet  spout,  start  the  motor  and  add  solvent 
from  time  to  time  as  required  until  the  effluent  is  clear.  After 
all  the  solvent  has  passed  off,  stop  the  motor  and  brush  the 
aggregate  out  of  the  bowl  on  to  the  paper  to  dry ;  then  weigh  the 
dried  aggregate.  Repeat  with  another  50  gm.  sample.  Calculate 
to  the  nearest  tenth  of  a  per  cent  the  amount  of  bitumen  extracted 
in  each  case  on  the  basis  of  original  weight  of  sample. 

Between  what  limits  does  the  percentage  of  bitumen  in  the 
wearing  surface  of  a  sheet  asphalt  pavement  usually  lie  ? 

References. 

1.  Bulletin  38,  Office  of  Public  Koads,  U.  S.  Department  of  Agricul- 
ture. 


[62] 


TEST  No.  36 
MELTING  POINT  OF  BITUMEN 

Purpose.    To  determine  the  melting  point  of  bitumen. 
Material.     About  50  gms.  of  bitumen. 

Apparatus.  Iron  tripod,  Bunsen  burner,  wire  gauze,  one  800 
cc.  Jena  glass  beaker,  one  400  cc.  Jena  glass  beaker,  iron  ring 
support,  burette  clamp,  object  glass,  metal  cover,  piece  No.  12 
wire  10  in.  long,  thermometer  reading  from  0°  to  250°  C.,  J  in. 
brass  cube  moulds  amalgamated,  amalgamated  brass  plate,  large 
kitchen  spoon,  spatula. 

Operations.  Bitumens  have  no  true  melting  point,  but  to 
determine  a  so-called  melting  point  the  following  arbitrary 
method  is  of  value  for  purposes  of  identification,  control,  and 
comparison. 

T$y  gentle  application  of  heat  melt  some  of  the  sample  in  the 
spoon  until  it  just  begins  to  flow,  then  pour  it  into  the  cube 
moulds  until  these  are  slightly  more  than  filled.  When  cool,  cut 
off  the  excess  with  a  hot  spatula  and  remove  the  cubes  from  the 
mould.  Bend  the  end  of  the  wire  at  right  angles  and  fasten  on 
to  it  one  of  the  cubes  by  piercing  the  center  of  opposite  sides 
of  the  cube.  Fill  the  large  beaker  about  half  full  with  water 
at  about  25°  C.  and  mount  it  over  the  gauze  on  the  tripod  ring 
so  that  heat  may  be  applied  from  below.  With  the  iron  ring 
support  suspend  the  smaller  beaker  as  far  down  as  possible  in  the 
water-bath.  Through  a  cork  in  the  metal  cover  suspend  the 
wire  which  holds  the  cube  so  that  the  base  of  the  latter  is  one 
inch  above  the  bottom  of  the  smaller  beaker.  Place  a  piece  of 
paper  flat  on  the  bottom  of  the  beaker  under  the  cube.  With 
the  burette  clamp  suspend  the  thermometer  through  the  circular 
portion  of  the  triangular  hole  in  the  metal  cover  so  that  the  bulb 
is  on  a  level  with  the  cube  and  at  an  equal  distance  from  the  side 
of  the  beaker. 

With  the  Bunsen  burner  heat  the  water  in  the  larger  beaker 
from  below  at  such  a  rate  that  the  thermometer  indicates  an 

[63] 


increase  of  5°  C.  per  minute.  The  temperature  at  which  the 
bitumen  touches  the  paper  at  the  bottom  of  the  beaker  is  taken 
as  the  melting  point.  If  necessary  read  the  thermometer  through 
the  object  glass,  which  is  to  be  placed  over  the  triangular  hole 
in  the  metal  cover  and  make  proper  allowance  for  inclination  of 
sight.  Determine  similarly  the  melting  point  of  the  other  cube. 

References. 

1.  Bulletin  38,  Office  of  Public  Koads,  U.  S.  Department  of  Agricul- 

ture. 

2.  Proceedings,  American  Society  of  Civil  Engineers,  Vol.  40,  No. 

10,  pp.  3043-3045. 

3.  Proceedings,  American  Society  for  Testing  Materials,  1914,  pp. 

503-507. 

4.  Proceedings,    American    Society    for    Testing    Materials,    1915. 

Eeport  of  Committee  D-4  with  appendices. 


[64] 


TEST  No.  37 

FIXED  CARBON 

Purpose.  To  determine  the  percentage  of  fixed  carbon  in 
bitumen. 

Material.    About  5  grams  of  bitumen. 

Apparatus.  Iron  ring  support,  Bunsen  burner,  porcelain 
triangle,  platinum  crucible  with  tight-fitting  cover  weighing  com- 
plete about  25  gm.,  crucible  tongs,  desiccator,  analytic  balance 
sensitive  to  one  tenth  of  a  milligram. 

Operations.  Accurately  weigh  the  crucible,  introduce  1  gm. 
of  bitumen,  then  accurately  weigh  again.  Cover  the  crucible 
securely  and  place  it  on  the  triangle.  Apply  heat,  first  gently, 
then  more  intensely  until  no  more  smoke  or  flame  comes  from 
between  lid  and  crucible.  Then  heat  for  seven  minutes  more, 
holding  down  the  cover  with  the  tongs.  The  bottom  of  the 
crucible  should  be  about  7  cm.  above  the  top  of  the  burner ;  the 
flame  should  be  about  20  cm.  high  when  burning  free.  The  outer 
surface  of  the  cover  should  burn  clear ;  the  inner  surface  may  or 
may  not  be  covered  with  carbon. 

Cool  the  crucible  in  the  desiccator;  then  weigh.  Then  open 
the  crucible  and,  holding  it  in  an  inclined  position  over  the 
burner,  ignite  the  contents  until  nothing  but  ash  remains.  Burn 
off  similarly  any  carbon  deposit  on  the  cover.  Again  cool  and 
weigh  crucible  and  cover  with  residual  ash.  Deduct  the  weight 
of  ash  from  the  weight  of  residue  after  first  ignition  of  sample. 
The  difference  equals  the  weight  of  fixed  carbon  which  is  to  be 
calculated  in  percentage  on  the  basis  of  total  weight  of  sample 
exclusive  of  mineral  matter. 

Repeat  with  another  1  gm.  sample. 

References. 

1.  Bulletin  38,  Office  of  Public  Eoads,  U.  S.  Department  of  Agricul- 

ture. 

2.  Proceedings,  American  Society  of  Civil  Engineers,  Vol.  40,  No. 

10,  pp.  3048-3049. 

3.  The  Modern  Asphalt  Pavement,  Eichardson,  p.  549. 

[65] 


TEST  No.  38 

DUCTILITY 

Purpose.    To  determine  the  ductility  of  bitumen. 

Material.    About  60  grams  of  bitumen. 

Apparatus.  Ductility  machine,  amalgamated  briquette  mould 
and  brass  plate,  three  thermometers  reading  from  0°  to  100°  C., 
three  rubber  stoppers  for  thermometers,  agate  dipper  with  spout 
for  melting  bitumen,  Bunsen  burner,  iron  ring  support,  spatula, 
asphalt  thermometer,  agate  pan,  agate  pot. 

Operations.  Heat  the  bitumen  gently  in  the  dipper  until  it 
just  begins  to  flow.  Place  the  mould  flat  on  the  amalgamated 
brass  plate  and  pour  into  it  the  moulten  bitumen  so  as  to  slightly 
more  than  fill  it.  When  the  bitumen  has  cooled  cut  off  the  excess 
with  a  heated  spatula.  Remove  only  the  sides  of  the  mould  and 
allow  the  briquette  to  remain  for  thirty  minutes  in  water  at  25° 
C.  Stir  the  water  from  time  to  time  with  the  asphalt  thermometer 
and  note  the  temperature;  maintain  this  temperature  by  adding 
hot  water  as  required. 

Carefully  lift  the  glass  cylinder  of  the  ductility  machine  up 
from  the  rubber  stopper,  and  by  means  of  the  ends  of  the 
briquette  mould  still  attached  to  the  briquette  fasten  it  between 
the  grips  of  the  machine  and  carefully  lower  the  glass  cylinder 
tightly  into  place.  Fill  the  glass  cylinder  with  water  at  77°  fahr. 
to  a  point  at  least  6  in.  above  the  top  of  the  briquette.  Take  up 
the  slack  between  the  grips  and  set  the  pointer  to  indicate  0  on 
the  scale.  Pull  the  briquette  apart  at  a  uniform  rate  of  5  cm. 
per  minute.  The  distance  the  pointer  moves  up  to  the  time  of 
rupture  of  the  briquette  indicates  the  ductility  of  the  bitumen. 
If  required  as  the  test  proceeds  add  more  water  to  the  glass 
cylinder  so  that  up  to  the  time  of  rupture  the  whole  briquette  is 
immersed  in  water  at  77°  fahr.  as  indicated  by  the  thermometers 


[66] 


introduced  through  the  rubber  stoppers  at  the  three  side  inlets 
to  the  glass  cylinder. 

Repeat  with  a  second  briquette. 

References. 

1.  Proceedings,  The  American  Society  of  Civil  Engineers,  Vol.  40, 

No.  10,  p.  3047. 

2.  Proceedings,    American    Society    for    Testing    Materials,    1915. 

Keport  of  Committee  D-4  with  appendices. 


[67] 


OIL 

TEST  No.  39 
FLASH  POINT 

Purpose.    To  determine  the  flash  point  of  a  bituminous  oil. 
Material.    About  800  cc.  of  oil. 

Apparatus.  New  York  State  Board  of  Health  oil  tester  with 
Bunsen  burner,  chemical  thermometer  reading  from  0°  to  400° 
C.,  6-millimeter  glass  tubing  about  6  centimeters  long  drawn  at 
one  end  to  a  1-millimeter  opening,  rubber  tubing  for  gas  con- 
nection for  glass  jet. 

Operations.  Remove  inner  oil  cup  and  pour  water  into  the 
bath  so  that  it  is  full  when  the  oil  cup  is  replaced.  For  oils 
which  flash  above  100°  C.  cottonseed  oil  must  be  used  in  the  bath 
instead  of  water.  Fill  the  oil  cup  with  the  sample  to  be  tested 
up  to  a  point  about  3  mm.  below  the  flange.  Place  the  glass  cover 
on  the  oil  cup  and  adjust  the  thermometer  so  that  its  bulb  is  just 
covered  by  the  bituminous  material.  Apply  heat  so  that  the 
temperature  of  the  test  sample  rises  at  the  rate  of  5°  C.  per 
minute.  The  test  flame  should  be  about  5  mm.  long.  When  near 
the  flash  point  insert  at  intervals  of  5°  C.  the  test  flame  through 
the  opening  in  the  cover  half  way  down  to  the  surface  of  the 
sample.  Take  the  temperature  at  that  insertion  of  the  test  flame 
which  causes  a  faint  bluish  flame  to  appear  over  the  surface  of 
the  sample.  This  temperature  is  the  flash  point. 

Repeat  the  determination. 

References. 

1.  Bulletin  38,  Office  of  Public  Beads,  U.  S.  Department  of  Agricul- 

ture. 

2.  Proceedings,  American  Society  of  Civil  Engineers,  Vol.  40,  No. 

10,  p.  3037. 

3.  The  Modern  Asphalt  Pavement,  Eichardson,  p.  554. 


[68] 


TEST  No.  40 

VISCOSITY 

Purpose.  To  determine  the  relative  viscosity  of  a  bituminous 
oil  and  water. 

Material.    About  160  cc.  of  bituminous  oil. 

Apparatus.  Engler  viscosimeter  with  thermometer,  100  cc. 
glass  graduate,  stop  watch,  thermometer  reading  from  0°C.  to 
100°  C.,  agate  pot,  Bunsen  burner  and  iron  ring  stand. 

Operations.  Clean  very  thoroughly  the  inner  cup  and  outlet 
tube.  Insert  the  thermometer  through  the  stopper  in  the  cover 
of  the  cup  so  that  its  bulb  is  near  the  bottom  of  the  cup  when 
the  latter  is  covered.  Put  the  wooden  stopper  in  place  and  the 
glass  graduate  directly  under  the  outlet  so  that  as  the  water 
flows  out  it  will  not  first  touch  the  sides  of  the  graduate.  Fill 
the  bath  with  water  and  apply  heat  gently  until  the  temperature 
of  the  bath  is  77°  fahr.  Agitate  the  bath  occasionally  with  the 
stirrer  while  this  temperature  is  being  maintained.  Fill  the  inner 
cup  with  water  at  77°  fahr.  up  to  the  top  of  the  projections.  By 
means  of  the  flame  from  the  ring  burner  under  the  bath  regulate 
the  temperature  of  the  water  in  the  inner  cup  to  remain  constantly 
at  77°  fahr.  for  at  least  three  minutes,  then  remove  the  stopper 
and  with  the  stop  watch  determine  to  the  nearest  0.2  second  the 
time  required  for  50  cc.  and  100  cc.  to  flow  out.  Repeat  the 
determination  with  water,  then  make  two  similar  determinations 
with  the  bituminous  oil.  Take  the  mean  values  as  the  results. 

The  time  in  seconds  required  for  a  given  volume  of  oil  at 
77°  fahr.  to  pass  through  the  viscosimeter  divided  by  the  similar 
time  for  the  same  volume  of  water  at  77°  fahr.  equals  the  specific 
viscosity  of  the  oil  at  77°  fahr.  for  the  given  volume.  Calculate 
the  specific  viscosities  of  the  bituminous  oil  for  volumes  of  50  cc. 
and  100  cc.  Give  the  principal  dimensions  of  the  Engler  viscosi- 
meter. 


[69] 


References. 

1.  Bulletin  38,  Office  of  Public  Roads,  U.  S.  Department  of  Agricul- 

ture. 

2.  Proceedings,  The  American  Society  of  Civil  Engineers,  Vol.  40, 

No.  10,  pp.  3040-3041. 

3.  Proceedings,  American  Society  for  Testing  Materials,  1914,  pp. 

565-616. 

4.  Proceedings,    American    Society    for    Testing    Materials,    1915. 

Report   of  Committee   D-2,   Conversion   Tables   for   Saybolt 
Universal,  Engler  and  Redwood  Viscosimeters. 


[70] 


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